The formula doctors use to evaluate treadmill stress tests, and thereby assess heart health, doesn't account for important differences between men and women, a new study contends, reports webmd.com. A revised formula would better determine peak exercise rate, or the maximum number of heart beats per minute, for each sex, the researchers said.

For the new study, a team led by Dr. Thomas Allison, director of stress testing at the Mayo Clinic in Rochester, Minn., reviewed 25,000 stress-test results. They saw significant differences between men and women.

Allison's group found that although peak heart rate declines with age for both sexes, the rate declines more gradually in women. 

The findings are scheduled for presentation Saturday at the annual meeting of the American College of Cardiology, in Washington, D.C.

Based on their findings, the study authors developed a new formula.

According to the revised formula, the maximum heart rate for women aged 40 to 89 should be 200 minus 67 percent of their age. For men, the preferred formula is 216 minus 93 percent of their age, the study authors said.